@PseronWyrd as stated give us the option to smash open a window and enter through it! Even if the windows are boarded up for Artistic and back drop we could still enter them might create some real spooky situations where only with your Pip Boy light can you even see due to the wood covering all the buildings windows. With these wood coverings would be neat to see a crow bar feature. Like lock picking strength can gain you access.

What you see inside those boarded up houses is the outdoors. They have no interior graphics and the exterior graphics are transparent from the inside. You can see this on a PC by use of TCL in the console.